Author: Marvel P. Miller

Publisher:

Published: 1931

Total Pages: 10

ISBN-13:

The National Advisory Committee for Aeronautics has adopted the practice of measuring the moments of inertia of all airplanes that become available through their use in flight research work. This paper, which is the first of a series presenting the results of such measurements, gives the momumental ellipsoids of ten army and naval biplanes and one commercial monoplane. The data wer obtained by the use of a pendulum method, previously described. The moments of inertia are expressed in coeffienct as well as in dimensional form, so that those for airplanes of widely spaced different weights and dimensions can be compared. The coefficients are also useful for estimating the moments of inertia of airplanes for which no measurements of inertia can be computed. To determine the accuracy with which the moments of inertia can be computed from design data, calculations were made of the monents of inertia for one of the above airplanes by summing up the moments of inertia of its constituent parts. It was found that computed values were in error 20, 10, and 5 percent for the X, Y, and Z axes, respectively.